In most cases one would use the whole unformatted disk as a device for ScaleIO, but sometimes this is not possible. To use the free space from already partitioned disk ScaleIO sds component has a command line tool called create_file_storage. It is located in the ScaleIO sds component folder. Tool will create a pre-allocated file with specified size to a specified location.
Command to create file:
create_file_storage −−create_file −−size_gb <SIZE_IN_GB> −−file_name <FILE_NAME>
create_file_storage −−create_file −−size_gb 120 −−file_name C:scaleio_devicesfile1.io
When adding a devices for SDS specify the full path of the file as the “Path” for the device.
The “file as device” options allows to start consuming free space for ScaleIO from disks that have existing partitions and existing file systems.